REGION: Tsunami alert helped gauge county's emergency readiness

Researchers visit county to assess Friday's tidal surge

The tsunami caused by the 9.0-magnitude quake that devastated
Japan on Friday barely registered on San Diego County beaches, but
preparations for the tidal surge that arrived in the region later
that morning served as good experience in case of much larger
waves, emergency officials said.

Friday's waves also will help researchers study tsunamis in San
Diego County, where about 25,000 people live in areas at risk of
flooding. Two scientists with the Tsunami Research Center at the
University of Southern California were in the county Tuesday
assessing the effect of the waves.

Last Thursday, the county's Office of Emergency Services
received an alert of a possible tsunami at about 11:55 p.m. after a
magnitude 9.0 earthquake off the coast of Japan.

Early Friday morning, emergency officials were told by the West
Coast and Alaska Tsunami Warning Center in Alaska to expect 2- to
3-foot waves in the region as a result of the earthquake, said Ron
Lane, the county's emergency services director.

The center issues three kinds of alerts: a watch, an advisory
and a warning. A watch is the earliest alert of a possible tsunami;
an advisory means a tsunami could produce strong currents in the
water; and a warning means the tsunami could produce coastal
flooding and waves over 3 feet.

A 8.8-magnitude earthquake in Chile last year prompted a similar
alert and similar size waves, so local officials knew what to
expect, Lane said.

"The more often you do this, the better feel you have," he said.
"It just gives us better reference for the waves."

About 1 a.m. Friday morning, the county's Office of Emergency
Services held a conference call with the 18 cities in the county to
discuss the tsunami advisory. There were several other calls with
the state's Emergency Management Agency throughout the morning,
Lane said.

About 6 a.m., emergency center personnel held another conference
call with all coastal cities, the U.S. Coast Guard and police to
discuss their response to the tsunami. By then, officials expected
smaller waves similar to those after the Chilean earthquake in
2010, which resulted in relatively little damage, Lane said.

Based on the information it received, the county officials
decided to issue an advisory that included:

-- Encouraging people to stay out of the water and away from the
coastline;

-- Discouraging people from going to the beach or harbors to
look at the tsunami;

-- Asking people to stay informed about updates through official
emergency hotlines and websites.

No major damage was reported and no one was injured in the
county as a result of the nearly 3-foot waves that hit the region's
beaches starting about 8:40 a.m. Friday morning. But the experience
did help emergency officials prepare, Lane said.

If the county had received a tsunami warning from the center,
Lane said, officials would have taken additional steps to evacuate
people within the region's tsunami inundation areas. These areas
were mapped by authorities as potential flooding zones in the event
of a tsunami.

Better data

An estimated 25,000 people live within tsunami inundation areas,
which are primarily along the county's beaches and a few lower
areas that can reach as far inland as Interstate 5 and El Camino
Real in North County, according to authorities.

The inundation maps were created by the tsunami researchers,
including those at the Tsunami Research Center. The maps are based
on computer models of tsunami events and large underwater
landslides that can produce waves of up to 40 feet.

In California, tsunamis are rare events that produce mostly
smaller waves, according to researchers.

Geologist Mark Legg and USC engineering professor Aggeliki
Barberopoulou were in San Diego and Oceanside on Tuesday to speak
with authorities and others about Friday's tsunami waves, including
their size and the kind of damage they caused. That information
will be used to improve inundation maps and to better understand
tsunamis in Southern California, Legg said.

"This will provide us with actual data to calibrate our models,"
Legg said.

Barberopoulou said they would discuss their preliminary findings
on Friday.

During last Friday's tsunami advisory, lifeguards and police
said they advised people to stay out of the water, but did not
force people out.

Police officers "did make announcements at the harbor asking
people to voluntarily leave their boats and the harbor," said
Oceanside police Lt. Leonard Mata. "The Police Department also made
announcements to people on The Strand, to people on the beach and
the lifeguards made announcements at the beach, the jetty and the
harbor."

Roughly 200 people were at the Oceanside Municipal Pier on
Friday morning, most of them local residents and amateur
photographers, watching for the tsunami. About a dozen surfers were
on the water, but there was relatively little evidence of the
tsunami.

About 2:30 a.m. Friday, lifeguards in Del Mar set up a command
center as a precaution, said lifeguard Tomas Bryant. But after the
tsunami hit the shores of Hawaii about 5 a.m., causing no serious
damage, lifeguards knew the chances of damage in Southern
California were largely diminished, Bryant said.

Early in the morning, lifeguards drove along the beach in Del
Mar advising surfers and joggers to stay out of the water. Most
people complied, but there were a few surfers who did not, Bryant
said.

Other North County lifeguards said their situations were
similar.

"We had staff come in at 6 a.m. and went up and down the beach
keeping people out of the water," said Solana Beach lifeguard Grant
Fletcher. "We advised them, we didn't mandate that they get out,
but they were pretty compliant."

Fletcher added: "We knew it wasn't much of an event, but the
reality is that it was a good drill for everybody."